I came across DNxHD just a short while ago, searching for a solution to be able to fluent edit my videos from various occasions. So far it was a bit of a problem since the video editing software had trouble to decode it fast enough (we speak about 1920×1080 AVC video), and so it was a pain to just cut them into pieces. But with DNxHD its piece a cake, the only downside is the fact it need a lot of space (8 min equals ~11 gb when the video is 1920×1080) but the positive aspect is that its visually lossless. Before I used H264 lossless mode, but yea, same problems as with the AVC files from the cam itself, through a bit better since its not in M2TS format anymore. I really wish they would finally add VDAPU (nvidia) and its AMD counterpart to the known video editors. Anyway, to convert a source m2ts to our DNxHD mov (yes, Quicktime, otherwise it won’t work) just do the following on a console after navigating into your video folder:
avconv -i 20120526130908.m2ts -vcodec dnxhd -b 185M -s 1920x1080 -aspect 16:9 -deinterlace -r 25 -acodec pcm_s16be -v verbose -y Shiroku_live_1080_dnxhd.mov
Here I convert the live performance of Shiroku that I captured on the Dokomi this year into DNxHD for editing. The file also needs deinterlacing and decimate since its taken in 50i. If you capture in 60i (NTSC) you want to change the “-r 25″ to “-r 30″. Also you can change here already the resolution if you plan to use a lower res later or your camera actually takes a lower res. To do so change the “-s HxW” parameter, for example for 720p go for “-s 1280×720″. When you change the picture size you also can change the video bit rate. I found a useful table at this page. Currently ffmpeg just support 8 bit DNxHD, and through that our video editing software also only support 8 bit since practically all software on Linux use ffmpeg for de/en-coding in the end. If you system don’t have “avconv” just replace it with “ffmpeg”. I migrate from the ffmpeg to the avconv command since with ffmpeg-0.8 the “ffmpeg” command is marked as legacy. Also I found it quite useful to export from my video editing software to DNxHD, and encode the material with Handbrake. The DNxHD export works way faster than the usual H264 export, and Handbrake tends to encode the H264 more efficient then the video editing software does. If you still look for software to edit with, here is a list of software I use(d):
- Kdenlive – http://www.kdenlive.org/
- OpenShot – http://www.openshotvideo.com/
- Cinelerra CV – http://cinelerra.org/
And if you have suggestions for more video editing software, just post a comment. I’m always open to try something new.